Field of the Invention
The present invention relates to a processing apparatus such as a laser processing apparatus, cutting apparatus, and grinding apparatus for performing predetermined processing to a workpiece such as a wafer.
Description of the Related Art
In a semiconductor device fabrication process, a plurality of crossing division lines are formed on the front side of a substantially disk-shaped wafer to thereby define a plurality of separate regions where a plurality of devices such as ICs and LSIs are formed. The back side of the wafer is ground to reduce the thickness of the wafer to a predetermined thickness, and the wafer is next cut along the division lines to thereby divide the regions where the devices are formed from each other, thus obtaining a plurality of individual device chips.
The back side of the wafer is ground by using a grinding apparatus including a chuck table for holding the wafer, grinding means having a grinding wheel for grinding the wafer held on the chuck table, and measuring means for measuring the thickness of the wafer (see Japanese Patent Laid-Open No. 2002-319559, for example).
The wafer is divided along the division lines by using a cutting apparatus or a laser processing apparatus. The cutting apparatus includes a chuck table for holding the wafer, cutting means having a cutting blade for cutting the wafer held on the chuck table, and imaging means for detecting the division lines formed on the wafer held on the chuck table (see Japanese Patent Laid-Open No. Hei 7-45556, for example).
The laser processing apparatus includes a chuck table for holding the wafer, laser beam applying means for applying a laser beam to the wafer held on the chuck table, and imaging means for detecting the division lines formed on the wafer held on the chuck table (see Japanese Patent Laid-Open No. 2008-12566, for example).
In the cutting apparatus or the laser processing apparatus, a cut groove or a laser processed groove is imaged by the imaging means to detect the condition of the cut groove or the condition of the laser processed groove. Accordingly, the processing conditions can be adjusted according to the condition detected above (see Japanese Patent Laid-Open No. Hei 5-326700, for example).